#include <fstream>
#include <vector>
using namespace std;
const int nmax=100005;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> muchii[nmax];
bool viz[nmax];
int n, m, cc;
void dfs(int nod)
{
    viz[nod]=true;
    for (int i=0; i<muchii[nod].size(); i++)
    {
        int vecin = muchii[nod][i];
        if (!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    fin >> n >> m;
    for (int i=1; i<=m; i++)
    {
        int x, y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
    {
        if (!viz[i])
        {
            cc++;
            dfs(i);
        }
    }
    fout << cc;
    return 0;
}